is absent in the articular cartilage in the joints and fibrocartilage in the joint capsules, at the attachment points of tendons and ligaments to bones and in the intervertebral discs in the spine 1.

In children before puberty, perichondrium covers cartilage at the same sites as in adults AND the articular cartilage.

Structure (Histology)

Perichondrium consists of two layers:

The outer fibrous layer, which is made of dense irregular connective tissue, which contains the cells called fibroblasts, which produce collagen fibers type I

The inner chondrogenic layer contains fibroblasts, which can produce chondroblasts and chondrocytes

Small blood vessels

References: 5,7

Function

Perichondrium contributes to appositional cartilage growth and repair, which is good in growing individuals but poor in adults 3,6,7. Articular cartilage, which does not have perichondrium has very poor regeneration ability after damage 3. Fibrocartilage cartilage, which also lacks perichondrium undergoes interstitial growth 9.

During endochondral ossification at the bone collar, perichondrium produces osteoblasts and thus bone, and the perichondrium itself becomes periosteum 8.

In early bone development, perichondrium might serve as a reservoir of mesenchymal stem cells that can develop into osteoblasts, adipocytes and chondrocytes 10.

Perichondrium is involved in cartilage nourishment. Nutrients diffuse from capillaries in the perichondrium to cartilage, which is avascular (contains no vessels) 5.

Perichondrium contributes to the strength and stiffness of the costal cartilage in the ribs 2.

The information is contractive.
The photo shows the articular cartilage with a perichondrium.
However, later below where the functions are stated, it says:
“Articular cartilage, which does not have perichondrium has very poor regeneration ability after damage.”